Photo of a clam with close up images below.
Increasingly high-resolution images of a Tridacna clam cross-section showing its banding pattern. Credit: Arndt et al. [2023], Figure 1 (modified)
Editors’ Highlights are summaries of recent papers by AGU’s journal editors.
Source: Geochemistry, Geophysics, Geosystems

Geochemical measurements of the mollusk Tridacna (giant clam) provides climate data of past environments. Assigning time to these data requires age chronologies, often determined from regular optical shell banding patterns. However, these growth bands are often difficult to visualize in fossil specimens.

Arndt et al. [2023] present a new approach using a script in Python to retrieve paleoenvironmental information from fossilized Tridacna clams on daily timescales. Cyclic daily variation in shell geochemistry enables daily-scale changes in growth rates and thus elemental composition. Application of this technique will provide unprecedented opportunities to bridge the gap between short-term weather patterns and longer-term climate variability.

Citation: Arndt, I., Coenen, D., Evans, D., Renema, W., & Müller, W. (2023). Quantifying sub-seasonal growth rate changes in fossil giant clams using wavelet transformation of daily Mg/Ca cycles. Geochemistry, Geophysics, Geosystems, 24, e2023GC010992.

—Branwen Williams, Editor, G-Cubed

Text © 2023. The authors. CC BY-NC-ND 3.0
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